Persistence of antibody to 23-valent pneumococcal polysaccharide vaccine: a 5-year prospective follow-up cohort study

Pneumococcal vaccines are effective in preventing pneumococcal diseases in adults. The evaluation of the antibodies persistence to the 23-valent pneumococcal polysaccharide vaccine (PPV23) could provide evidence on PPV23 revaccination. Adults aged ≥ 60 years were selected and vaccinated with PPV23 in Shanghai, and followed up for 5 years with blood samples collection of a 1-year interval. The geometric mean concentrations (GMC) of the IgG against 23 pneumococcal serotypes covered by PPV23 were detected using enzyme-linked immunosorbent assay. The antibodies to 23 pneumococcal serotypes among different groups was analyzed using statistical analysis. Overall, 517 participants completed all six visits over a 5-year period (2013–2018). The GMC of 23 serotypes in adults aged ≥ 60 years decreased slowly after PPV23 vaccination compared to baseline pre-vaccination (<i>P</i> &lt; 0.05), except serotype 3. Additionally, the multiplicative increase in the antibody concentration after PPV23 vaccination was greater, and the antibody levels of serotypes 1 and 6B were significantly higher at visit 5 than at visit 4 (<i>P</i> &lt; 0.05). The pneumococcal antibodies in elderly after PPV23 vaccination could sustain high levels over long-term follow-up, which suggested that the interval of revaccination with PPV23 in elderly should be at least 5 years after the first vaccination.